Mineral material such as stone is obtained from the soil for crushing either by exploding or by digging. Stone can be natural stone and gravel or building waste. Both movable and stationary crusher applications are used in crushing. The material for crushing is fed by an excavator or a wheel loader into the feed hopper of the crusher or crushing plant wherefrom the material to be crushed can fall into the jaw of the crusher, or the feeder can transfer the stone material toward the crusher. The mineral material for crushing can also be recyclable material such as concrete, brick or asphalt.
Gyratory and cone crushers are usually used after the jaw crusher for intermediate and fine crushing. In that case, the objective is to produce for example gravel or fine sand. Gyratory and cone crushers break up all stone types but not always recycled materials. Large primary cone crushers are used in mines in the primary crushing phase as well as in other mining and quarrying applications that demand large capacity.
A thrust bearing is arranged in the lower end of the vertically movable main shaft of the gyratory crusher, consisting of a lower bearing, an upper bearing and a pressure plate between the lower and upper bearing. In some cases, in connection with lifting the main shaft, the pressure plate has stuck onto the upper bearing through the oil membrane and fallen uncontrollably. The falling of the pressure plate has damaged the lower bearing or other structures.
WO9715396A1 presents a cone crusher with an axial thrust bearing.
The objective of the invention is to avoid or mitigate problems related to the field of technology and/or to provide new technical alternatives. An objective of the invention is to prevent damaging of the structures of the thrust bearing and the crusher in connection with lifting the main shaft.